Incinerator system

ABSTRACT

An incinerator system which minimizes the emission of pollutants into the atmosphere is disclosed. The system includes an afterburner which receives the exhaust material of an incinerator, and which is preferably constructed of rhyolite material having only minimal traces of iron oxides. The afterburner includes a passageway having a constricted venturi section which expands and accelerates the exhaust materials to maximize the combustion thereof at a relatively moderate temperature. The incinerator itself and the afterburner can be constructed of a unitary block of cast rhyolite material.

United States Patent [191 Hemrich [4 1 Aug. 26, 1975 l 5 4 l INCINERATOR SYSTEM [76] Inventor: Ray F. Hemrich, P.O. Box 610,

Altaville, Calif. 95221 [22] Filed: July 5, 1974 [21] Appl. No.1 486,049

[52] US. Cl 110/8 R; 110/18 R; 110/119 [51] Int. Cl. F23G 5/00 [58] Field of Search 110/8 R, 8 A, 8 C, 18 R, 1 10/18 C, l 19 [56] References Cited UNITED STATES PATENTS 3,310,009 3/1967 Jacobs llO/8 A 3,495,555 2/1970 Boyd et 31.. 3,530,806 9/1970 Bowman 110/8 A 3,605,654 9/1971 Bowles, Jr 110/8 A 3,651,771 3/1972 Eberlc 110/8 A FOREIGN PATENTS OR APPLICATIONS 898,237 6/1962 United Kingdom 110/8 A Primary ExaminerKenneth W. Sprague Attorney, Agent, or FirmTownsend and Townsend 5 7 ABSTRACT An incinerator system which minimizes the emission of pollutants into the atmosphere is disclosed. The system includes an afterburner which receives the exhaust material of an incinerator, and which is preferably constructed of rhyolite material having only minimal traces of iron oxides. The afterburner includes a passageway having a' constricted venturi section which expands and accelerates the exhaust materials to maximize the combustion thereof at a relatively moderate temperature. The incinerator itself and the afterburner can be constructed of a unitary block of cast rhyolite material.

14 Claims, 6 Drawing Figures 1 ll gg I.

ill 1 lllll PAIENTEmuszsiQvs 3,901 168 SHEET 2 UF 2 PATENTED Ans-261975 I mum INCINERATOR SYSTEM BACKGROUND OF THE INVENTION The present invention relates to an incinerator system, and in particular to incinerator systems having pollution control measures.

The incineration of waste material using only a single burning stage has been found totally unacceptable in crowded urban areas. Such incineration produces a relatively large amount of particulate matter which contaminates the atmosphere to an unacceptable level. Various systems have evolved for factory use to minimize the passage of such particulate matter into the atmosphere, but these systems are generally very expensive to implement and are relatively complex, making them economically unfeasible for relatively smaller installations such as restaurants and other small businesses. Such businesses therefore usually cannot meet pollution control requirements imposed by current regulations, and as a result disposing of waste material by incinerating is effectively banned for such businesses in urban areas. Instead, the waste material is usually hauled away by truck and used as a land fill which is expensive and often destroys the natural environment of the area in which the land fill is located.

An obvious solution to the problem of producing excessive particulate matter by incinerating with a single burning stage is to add a second burning stage, called an afterburner stage, to process the exhaust material of the first burning stage. The problem with this solution is that excessive heating of the exhaust gases to combust the particulate matter will cause the formation of gaseous elements, such as oxides of nitrogen, which can form the basis for photochemical smog. Thus, uncontrolled excessive heating of the exhaust gases solves one problem but merely creates another, changing the form of the pollution from particulate matter to photochemical smog.

SUMMARY OF THE INVENTION The present invention provides an afterburner having a passageway which is traversed by the exhaust material from the incinerator before it reaches the atmosphere. The passageway is preferably formed or at least lined with rhyolite material having very little iron or iron oxides. A constricted venturi section is interposed in the passageway and expands and accelerates the exhaust material and reduces the pressure of the exhaust gases. As a result, the exhaust material is more fully combusted and particulate matter therein is minimized. The rhyolite material collects heat energy from the combustion of the material and re-radiates it back into the passageway to sustain and Stabilize the combustion process.

In the preferred embodiment of the present invention, the venturi section is located in an elongate portion of the passageway and a burner is provided upstream of the venturi section to initiate combustion of the particulate matter in the afterburner. Downstream of the venturi section, the accelerated exhaust material encounters a sharp corner in the passageway which in creases the turbulence of the material, further increasing the combustion thereof. After the sharp corner, the gases pass into a dead-end section of the passageway where it is recirculated to again enhance the combustion of the particulate matter. The exhaust material is then passed through a scrubbing unit to remove most of that particulate matter still remaining before the exhaust material is released to the atmosphere.

The preferred embodiment of the present invention is constructed of rhyolite material having only minimal traces of oxides of iron. Rhyolite material is generally available, but most such material contains substantial quantities of iron and iron oxides. This type of rhyolite cannot withstand the high temperatures encountered in an incinerator, particularly in the afterburner section, and cannot be effectively used in the instant application. However, rhyolite material containing only traces of iron as in the present invention provides a good refractory material capable of withstanding the temperatures encountered in the incinerator. In addition, the rhyolite material serves to absorb a significant portion of the heat energyproduced by the combustion, both in the incinerator and in the afterburner, and reradiates this thermal energy internally to sustain combustion therein. The rhyolite material thus serves as a combined heat sink and source to stabilize the temperature at which combustion takes place, preventing over-heating of the exhaust material which can form oxides of nitrogen and other elements of photochemical smog. Also, such re-radiation of the heat energy minimizes or eliminates the heat input required from burners in the incinerator and afterburner after combustion has been started to minimize the fuel consumption of the system as a whole. The entire system of the present invention exclusive of the burners and other peripheral equipment can be formed from a single cast block of rhyolite material for efficient construction of an integral waste disposal system.

The novel features which are believed to be characteristic of the invention, both as to organization and method of operation, together with further objects and advantages thereof will; be better understood from the following description considered in connection with the accompanying drawings in which a preferred embodiment of the invention is illustrated by way of example. It is to be expressly understood, however, that the drawings are for the purpose of illustration and description only and are not intended as a definition of the limits of the invention.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a perspective view of the apparatus of the present invention;

FIG. 2 is a perspective view of the cast block of the present invention with portions of the apparatus broken away;

FIG. 3 is a cross sectional view taken along lines 33 of FIG. 2;

FIG. 4 is a cross sectional view taken along lines 44 of FIG. 2;

FIG. 5 is a cross sectional view taken along lines 55 of FIG. 2;

FIG. 6 is an exploded view of blocks used in casting the rhyolite material.

DESCRIPTION OF THE PREFERRED EMBODIMENT The overall configuration of the preferred embodiment 10 of the present invention is illustrated by way of reference to FIG. 1. Incinerator system 10 consists primarily of a unitary cast block of rhyolite material I2. Block 12 is provided with a door 14 at one end for the insertion of waste material to the incinerator portion of the block, which will be illustrated in more detail hereinafter. Ashes and other residue left by the burning of the waste material are withdrawn from within block 12 using tray 16. An aperture is provided in one side of block 12 for the installation of a burner 17 which is used to ignite the waste material initially. Another aperture is provided in the block for a second burner 19 which forms part of the afterburner stage of incinerator 10. A rectangular depression 22 is provided in the same side of block 12 as burners l7 and 19 for the placement of a water pump used in the scrubber portion of the apparatus. Exhaust gases from the incineration of the waste material exit the incinerator system through stack 24. A fan is located in housing 26 to increase the draft of stack 24.

Except for peripheral equipment such as the burners 17 and 19 and other fittings such as door 14 and tray 16, the upper portion of block 12 comprises a unitary cast block of rhyolite material. A floor 28, also of cast rhyolite material, forms the lower portion of incinerator 10. The interior cavities of incinerator 10 are formed in the rhyolite material itself so that the rhyolite is in direct contact with the combustion which occurs inside the incinerator. As a result, rhyolite material containing substantial quantities of oxides of iron can not be used because the iron oxides will be melted or vaporized by the intense heat. However, in the present invention, rhyolite having only small traces of oxides of iron is used. A specific rhyolite material which has been found acceptable for the purposes of the present invention has the following composition:

Loss on Ignition It should be noted that the iron oxide content is only 0.4 percent which is substantially smaller than the iron oxide content found in most rhyolite material. Some of the iron oxides may represent part of the loss on igni tion, and it is estimated that the total iron oxide content is less than approximately one percent.

Block 12 is preferably formed by casting the rhyolite material which is in the form of aggregate. A mixture in the proportion of three parts by volume rock, two parts sand, and one part cement and the appropriate amount of water has been found to provide a relatively strong rigid block suitable for the purposes of the present invention. Both the rock and the sand are rhyolite, the rock having diameters generally in the range of A2 to /8 inch, and the sand having diameters in the range of A: inch and smaller. The use of standard Portland or other cement, which is not rhyolite based has been found advantageous to increase the strength of the block, but such cement is not essential in forming cast rhyolite into a block.

The internal configuration of incinerator 10 is more fully illustrated by way of reference to FIG. 2 wherein portions of block 12 are broken away, and FIGS. 3-5 which are cross sectional views taken from FIG. 2. The left hand portion of block 12 includes a large cavity 40 which provides the incinerator stage wherein waste material is initially combusted. Such combustion is started and usually maintained in part by means of the burner which projects through aperture 18 in the side of block 12. After combustion has started, the thermal energy generated by the burner in aperture 18 can be reduced since the material itself will at least partially sustain the combustion. In addition, the rhyolite material absorbs heat energy from such combustion and re-radiates the energy back into cavity 40, serving to control and to sustain the combustion. Periodically, the ashes produced by such combustion can be removed through aperture 42 in the side of the block by means of the tray illustrated in FIG. 1.

Exhaust material from the combustion in cavity 40 exits the cavity through a relatively small rectangular passageway 44 adjacent the top of the cavity near one side thereof. Such exhaust material includes both exhaust gases and particulate matter suspended in the ex haust gases which was not fully combusted in cavity 40. From passageway 44, the exhaust material passes through a transverse elongate passageway 46 from one side of block 12 to the other. The exhaust material is further heated by a burner (not shown) located in aperture 20 at the upstream end of elongate passageway 46. Exhaust material thus heated passes through a constricted venturi portion 48 of passageway 46, which expands and accelerates the exhaust material. Due to the increased velocity of the material, the pressure of the gases decreases, and combustion of the particulate matter in the exhaust material is increased.

The downstream end 50 of passage 46 terminates in a square corner 52, at which point the exhaust material is directed downwardly through passageway 54. Turning through sharp corner 52 will induce turbulence in the stream of exhaust material which increases the combustion of the particulate matter. The lower end 56 of passageway 54 terminates in a dead-end portion through which the exhaust material cannot pass. The material thus recirculates as illustrated by arrows 58 to further combust the particulate matter. An exit pas sageway 60 for the exhaust material is provided at the center of passageway 54 to allow the material to pass from the afterburner stage through the scrubber stage. The passageway for the exhaust materials through the afterburner stage is isolated from rectangular depression 22, which is provided merely for placement of a water pump, as will be illustrated hereinafter.

Exhaust material exiting the afterburner stage passes into a scrubber unit by means of horizontal passageway 60 as illustrated in FIGS. 2 and 5. Scrubber unit 70 comprises a first chamber 72 separated from a second chamber 74 by means of curtain wall 76 which extends to a position several inches above the floor of block 12. Exhaust material initially passes into chamber 72, at which point it is cascaded with water 78 provided by sprinklers 80. From cavity 72, the exhaust material passes through the gap 82 between the lower end of curtain wall 76 and a quantity of water 84 in the bottom of scrubber unit 70. A plurality of sprinklers 86 are disposed along the lower ends of curtain wall 76 so that the exhaust material is further scrubbed as it passes through gap 82. The water level 84 is maintained at a preselected depth by drain 88 to maximize the scrubbing action through gap 82. After passing through gap 82, the exhaust materials flow upwardly through chamber 74 and out through aperture 90 to exit block 12.

In order to form the intricate passages in the cast rhyolite comprising the afterburner section of the present invention, a plurality of blocks are interconnected, as

illustrated in PK). 6. A rectangular block 100 will provide for depression 22 wherein the water pump is placed. Cylindrical block 102 provides aperture for the placement of the burner. Rectangular block 104 provides passageway 44, and has a cylindrical inset 106 adapted to mate with block 102. Venturi section 48 is formed with an irregularly shaped block 108, which has a cylindrical projection 110 on one end adapted to mate with a corresponding aperture 112 in rectangular block 104. A relatively long rectangular block 114 provides passageway 54, and has an aperture 116 adapted to mate with a cylindrical extension 118 on block 108. A smaller rectangular block 120 has a cylindrical projection 122 which mates with aperture 124 in rectangular block 114, and provides passageway 60. The blocks are combined together and in combination over the interior passages of the afterburner section. The blocks are constructed of cellulose or other relatively light material, and after the rhyolite has been cast, the blocks are merely burned out, leaving the desired passageways.

ln operation, waste material is inserted through door 14 into cavity 40 forming the incinerator stage of block 12. The door is then closed and the burner in aperture 18 turned on to initiate combustion in cavity 40. The rhyolite material forming cavity 40 absorbs a portion of the energy produced by the combustion, and glows to radiate the heat energy back into the cavity 40 to sustain and control the combustion therein. The burner in aperture 18 can then be de-activated or its output reduced as the combustion of the waste material proceeds.

Exhaust material from the combustion in cavity 40 passes out of the cavity through passageway 44 forming the first part of the afterbumers stage. Such exhaust material is primarily gaseous but also includes particu late waste material which is not fully combusted in the cavity 40. This particulate matter is ignited by a second burner located in aperture 20 and accelerated through a venturi 48 forming a portion of passageway 46. The venturi accelerates the gas and reduces the pressure thereof, enhancing combustion of the particulate matter. The exhaust material is then passed around a square corner 52 and into a dead-end portion 56 of the afterburner to further increase combustion of the particulate matter. The rhyolite material which defines the passageway of the afterburner stage absorbs heat energy from the burner in aperture 20 and from the ex haust material, and glows to radiate this heat energy back into the afterburner to sustain and control the combustion of the particulate matter therein. After exiting the afterburner stage, the exhaust material passes through a scrubber stage which removes most of the remaining particulate matter in theexhaust gases.

While a preferred embodiment of the present invention has been illustrated in detail, it is apparent that modifications and adaptations of that embodiment will occur to those skilled in the art. However, it is to be expressly understood that such modifications and adaptations are within the spirit and scope of the present invention, as set forth in the following claims.

What is claimed as new is:

1. An afterburner adapted to receive the exhaust material of an incinerator, said afterburner comprising a walled passageway constructed of rhyolite material having less than about one percent by weight of iron oxides adapted to be traversed by the exhaust material of the incinerator before .it reaches the atmosphere, said passageway havinga-con'stricted venturi section adapted to expandand accelerate the exhaust material so that said material is more fully combusted and particulate matter therein is minimized.

2. An afterburner as recited in claim 1 wherein the passageway has an elongate portion, the venturi section interposed in said elongate portion, the downstream end of said elongate portion terminating in a sharp corner to increase the turbulence of the exhaust material so that said material is more fully combusted.

3. An afterburner as recited in claim 1 wherein the passageway has a dead end portion for re-circulation of the exhaust material so that said material is more fully combusted.

4. An afterburner as recited in claim 1 and additionally comprising a scrubbing chamber at the end of said passageway, said chamber having sprinklers disposed at the top thereof to entrain particulate matter in the water cascading from said sprinklers to remove said particulate matter from the exhaust gases.

5. An afterburner as recited in claim 1 and additionally comprising a burner adjacent the upstream end of the constricted venturi section to heat the exhaust materials and increase the combustion thereof.

6. An afterburner adapted to receive the exhaust material of an incinerator before it reaches the atmosphere, said afterburner comprising:

a casing of rhyolite material having less than about one percent by weight of oxides'of iron, said casing having an internal cavity providing a passageway for' the passage of the exhaust material of the incinerator, said passageway having an elongate portion with a constricted venturi section interposed in the elongate portion to expand and accelerate the exhaust material and reduce the pressure of the exhausted gases so that the material is more fully combusted; and

a burner adjacent tothe upstream end of the constricted venturi section to heat the exhaust material at least initially to cause combustion of the particulate matter in said exhaust material, combustion in the passageway being sustained at least in part by absorption of heat energy from the exhaust material by the rhyolite material and from re-radiation of said absorbed heat energy back into the passageway.

7. An afterburner as recited in claim 6 wherein said casing of rhyolite material additionally includes an incinerator section for initial combustion of waste material, said incinerator communicating with the passageway so that exhaust material from said incinerator section passes into said passageway, the combustion in the incinerator section being sustained at least in part by absorption of heat energy from the combustion of the waste material by the rhyolite material and from reradiation of said absorbed heat energy back into the incinerator section.

8. A substantially pollution free incinerator system comprising:

a casing of rhyolite material, said rhyolite material having less than one percent by weight of oxides of iron, said casing including a first cavity providing an incinerator section for initial combustion of waste material and a second cavity communicating with said first cavity and providing an afterburner section adapted to receive the exhaust material from the incinerator and further combust said exhaust material and thereby reduce the particulate matter therein; and

a burner communicating with the first cavity in the casing to at least initiate combustion of the waste material in the incinerator section, combustion in the incinerator section and in the afterburner section being sustained at least in part by absorption of heat energy from the combustion of the material and from the exhaust material and from reradiation of said absorbed heat energy back into the incinerator section and the afterburner section.

9. An incinerator system as recited in claim 8 and additionally comprising a second burner communicating with the second cavity in the casing to at least initiate combustion of the exhaust material in the afterburner section.

10. An incinerator system as recited in claim 8 wherein said casing comprises a casing of cast rhyolite material.

11. An incinerator system as recited in claim 8 wherein said casing includes a third cavity communicating with said second cavity so that the exhaust material emanating from said second cavity passes through said third cavity, and additionally comprising means for cascading water downwardly through said third cavity to entrain particulate matter in the exhaust material.

12. An incinerator system as recited in claim 8 wherein the afterburner section of the casing includes a constricted venturi portion to expand the exhaust material so that said material is more fully combusted.

13. A substantially pollution free incinerator system comprising:

a casing of cast rhyolite material having less than one percent by weight of oxides of iron, said casing including a first cavity providing an incinerator section for initial combustion of waste material and a second cavity communicating with said first cavity and providing an afterburner section adapted to receive the exhaust material from the incinerator and further combust the particulate matter in said exhaust material, said afterburner section having an elongate portion having a constricted venturi section interposed therein;

a burner communicating with the first cavity in the casing to at least initiate combustion of the waste material in the incinerator section; and

a second burner communicating with the elongate portion of the second cavity at the upstream end thereof to heat the exhaust material at least initially as said material passes through the constricted venturi section to maximize the combustion of particulate matter in the exhaust material to reduce the emission of such particulate matter to the atmosphere.

14. An incinerator system as recited in claim 8 wherein said rhyolite material is adapted to absorb a portion of the heat energy from the combustion of the waste material and from the exhaust material and to reradiate said absorbed heat energy back into the incinerator section and the afterburner section to maintain combustion therein. 

1. An afterburner adapted to receive the exhaust material of an incinerator, said afterburner comprising a walled passageway constructed of rhyolite material having less than about one percent by weight of iron oxides adapted to be traversed by the exhaust material of the incinerator before it reaches the atmosphere, said passageway having a constricted venturi section adapted to expand and accelerate the exhaust material so that said material is more fully combusted and particulate matter therein is minimized.
 2. An afterburner as recited in claim 1 wherein the passageway has an elongate portion, the venturi section interposed in said elongate portion, the downstream end of said elongate portion terminating in a sharp corner to increase the turbulence of the exhaust material so that said material is more fully combusted.
 3. An afterburner as recited in claim 1 wherein the passageway has a dead end portion for re-circulation of the exhaust material so that said material is more fully combusted.
 4. An afterburner as recited in claim 1 and additionally comprising a scrubbing chamber at the end of said passageway, said chamber having sprinklers disposed at the top thereof to entrain particulate matter in the water cascading from said sprinklers to remove said particulate matter from the exhaust gases.
 5. An afterburner as recited in claim 1 and additionally comprising a burner adjacent the upstream end of the constricted venturi section to heat the exhaust materials and increase the combustion thereof.
 6. An afterburner adapted to receive the exhaust material of an incinerator before it reaches the atmosphere, said afterburner comprising: a casing of rhyolite material having less than about one percent by weight of oxides of iron, said casing having an internal cavity providing a passageway for the passage of the exhaust material of the incinerator, said passageway having an elongate portion with a constricted venturi section interposed in the elongate portion to expand and accelerate the exhaust material and reduCe the pressure of the exhausted gases so that the material is more fully combusted; and a burner adjacent to the upstream end of the constricted venturi section to heat the exhaust material at least initially to cause combustion of the particulate matter in said exhaust material, combustion in the passageway being sustained at least in part by absorption of heat energy from the exhaust material by the rhyolite material and from re-radiation of said absorbed heat energy back into the passageway.
 7. An afterburner as recited in claim 7 wherein said casing of rhyolite material additionally includes an incinerator section for initial combustion of waste material, said incinerator communicating with the passageway so that exhaust material from said incinerator section passes into said passageway, the combustion in the incinerator section being sustained at least in part by absorption of heat energy from the combustion of the waste material by the rhyolite material and from re-radiation of said absorbed heat energy back into the incinerator section.
 8. A substantially pollution free incinerator system comprising: a casing of rhyolite material, said rhyolite material having less than one percent by weight of oxides of iron, said casing including a first cavity providing an incinerator section for initial combustion of waste material and a second cavity communicating with said first cavity and providing an afterburner section adapted to receive the exhaust material from the incinerator and further combust said exhaust material and thereby reduce the particulate matter therein; and a burner communicating with the first cavity in the casing to at least initiate combustion of the waste material in the incinerator section, combustion in the incinerator section and in the afterburner section being sustained at least in part by absorption of heat energy from the combustion of the material and from the exhaust material and from re-radiation of said absorbed heat energy back into the incinerator section and the afterburner section.
 9. An incinerator system as recited in claim 8 and additionally comprising a second burner communicating with the second cavity in the casing to at least initiate combustion of the exhaust material in the afterburner section.
 10. An incinerator system as recited in claim 8 wherein said casing comprises a casing of cast rhyolite material.
 11. An incinerator system as recited in claim 8 wherein said casing includes a third cavity communicating with said second cavity so that the exhaust material emanating from said second cavity passes through said third cavity, and additionally comprising means for cascading water downwardly through said third cavity to entrain particulate matter in the exhaust material.
 12. An incinerator system as recited in claim 8 wherein the afterburner section of the casing includes a constricted venturi portion to expand the exhaust material so that said material is more fully combusted.
 13. A substantially pollution free incinerator system comprising: a casing of cast rhyolite material having less than one percent by weight of oxides of iron, said casing including a first cavity providing an incinerator section for initial combustion of waste material and a second cavity communicating with said first cavity and providing an afterburner section adapted to receive the exhaust material from the incinerator and further combust the particulate matter in said exhaust material, said afterburner section having an elongate portion having a constricted venturi section interposed therein; a burner communicating with the first cavity in the casing to at least initiate combustion of the waste material in the incinerator section; and a second burner communicating with the elongate portion of the second cavity at the upstream end thereof to heat the exhaust material at least initially as said material passes through the constricted venturi section to maximize the combustion of particulate matter In the exhaust material to reduce the emission of such particulate matter to the atmosphere.
 14. An incinerator system as recited in claim 8 wherein said rhyolite material is adapted to absorb a portion of the heat energy from the combustion of the waste material and from the exhaust material and to re-radiate said absorbed heat energy back into the incinerator section and the afterburner section to maintain combustion therein. 